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<FONT color="green">001</FONT>    package net.jmatrix.eproperties;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import java.util.regex.*;<a name="line.3"></a>
<FONT color="green">004</FONT>    <a name="line.4"></a>
<FONT color="green">005</FONT>    import org.apache.commons.logging.*;<a name="line.5"></a>
<FONT color="green">006</FONT>    <a name="line.6"></a>
<FONT color="green">007</FONT>    /**<a name="line.7"></a>
<FONT color="green">008</FONT>     * Static methods used to substitute tokens for values.<a name="line.8"></a>
<FONT color="green">009</FONT>     * <a name="line.9"></a>
<FONT color="green">010</FONT>     * Note: This class has some very tricky logic supporting 2 types of <a name="line.10"></a>
<FONT color="green">011</FONT>     * substitutions (partial and complete), nested tokens (${key.${env}}),<a name="line.11"></a>
<FONT color="green">012</FONT>     * and default values.  <a name="line.12"></a>
<FONT color="green">013</FONT>     * <a name="line.13"></a>
<FONT color="green">014</FONT>     * When changing this class you should: <a name="line.14"></a>
<FONT color="green">015</FONT>     * a) know what you are doing<a name="line.15"></a>
<FONT color="green">016</FONT>     * b) know the desired token substitution syntax and function.<a name="line.16"></a>
<FONT color="green">017</FONT>     * c) test extensively with many tokenized properties files.<a name="line.17"></a>
<FONT color="green">018</FONT>     * <a name="line.18"></a>
<FONT color="green">019</FONT>     * you have been warned.  Bemo, 21 July 2009.<a name="line.19"></a>
<FONT color="green">020</FONT>     */<a name="line.20"></a>
<FONT color="green">021</FONT>    public final class SubstitutionProcessor {<a name="line.21"></a>
<FONT color="green">022</FONT>       static Log log=LogFactory.getLog(SubstitutionProcessor.class);<a name="line.22"></a>
<FONT color="green">023</FONT>       <a name="line.23"></a>
<FONT color="green">024</FONT>       // This was the original (non-functional) regex.<a name="line.24"></a>
<FONT color="green">025</FONT>       //static final String TOKEN_REGEX = "\\$\\{.*?\\}";<a name="line.25"></a>
<FONT color="green">026</FONT>       // for nested token trial. This regex seems to work in parsing<a name="line.26"></a>
<FONT color="green">027</FONT>       // some standard files as well as nested token replacements... <a name="line.27"></a>
<FONT color="green">028</FONT>       // i'm leaving it in place, pending further testing.  17 mar 2009.  bemo.<a name="line.28"></a>
<FONT color="green">029</FONT>       static final String TOKEN_REGEX="\\$\\{[^\\$\\{\\}]+\\}";<a name="line.29"></a>
<FONT color="green">030</FONT>    <a name="line.30"></a>
<FONT color="green">031</FONT>       static final String COMPLETE_TOKEN_REGEX="^"+TOKEN_REGEX+"$";<a name="line.31"></a>
<FONT color="green">032</FONT>       <a name="line.32"></a>
<FONT color="green">033</FONT>       static final Pattern PARTIAL_PATTERN = Pattern.compile(TOKEN_REGEX);<a name="line.33"></a>
<FONT color="green">034</FONT>       <a name="line.34"></a>
<FONT color="green">035</FONT>       static final Pattern COMPLETE_PATTERN = Pattern.compile(COMPLETE_TOKEN_REGEX);<a name="line.35"></a>
<FONT color="green">036</FONT>    <a name="line.36"></a>
<FONT color="green">037</FONT>       public static int MAX_RECURSIVE_SUBSTITUTIONS=10;<a name="line.37"></a>
<FONT color="green">038</FONT>       <a name="line.38"></a>
<FONT color="green">039</FONT>       public static boolean debug=false;<a name="line.39"></a>
<FONT color="green">040</FONT>       <a name="line.40"></a>
<FONT color="green">041</FONT>       /** <a name="line.41"></a>
<FONT color="green">042</FONT>        * Public facing method.<a name="line.42"></a>
<FONT color="green">043</FONT>        * <a name="line.43"></a>
<FONT color="green">044</FONT>        * There are 2 types of substitutions: partial and complete.  Complete <a name="line.44"></a>
<FONT color="green">045</FONT>        * substitutions are only possible when the value is simply the token. <a name="line.45"></a>
<FONT color="green">046</FONT>        * Partial substitutions are string only.  Complete substitutions can <a name="line.46"></a>
<FONT color="green">047</FONT>        * replace a token with an object - like EProperties or List.<a name="line.47"></a>
<FONT color="green">048</FONT>        * <a name="line.48"></a>
<FONT color="green">049</FONT>        * Partial Substitution: <a name="line.49"></a>
<FONT color="green">050</FONT>        * key="This is a string with a ${token} value"<a name="line.50"></a>
<FONT color="green">051</FONT>        * <a name="line.51"></a>
<FONT color="green">052</FONT>        * Complete Substitution:<a name="line.52"></a>
<FONT color="green">053</FONT>        * key2=${token}<a name="line.53"></a>
<FONT color="green">054</FONT>        * <a name="line.54"></a>
<FONT color="green">055</FONT>        * The result of a partial substitution is ALWAYS a String.  The result<a name="line.55"></a>
<FONT color="green">056</FONT>        * of a complete substitution can be any of [ String, EProperties, List ].<a name="line.56"></a>
<FONT color="green">057</FONT>        * <a name="line.57"></a>
<FONT color="green">058</FONT>        */<a name="line.58"></a>
<FONT color="green">059</FONT>       public static final String processSubstitution(String s, EProperties p) {<a name="line.59"></a>
<FONT color="green">060</FONT>          return (String)processSubstitution(s, p, String.class);<a name="line.60"></a>
<FONT color="green">061</FONT>       }<a name="line.61"></a>
<FONT color="green">062</FONT>       <a name="line.62"></a>
<FONT color="green">063</FONT>       public static final boolean containsTokens(String s) {<a name="line.63"></a>
<FONT color="green">064</FONT>          Matcher matcher=PARTIAL_PATTERN.matcher(s);<a name="line.64"></a>
<FONT color="green">065</FONT>          return matcher.find();<a name="line.65"></a>
<FONT color="green">066</FONT>       }<a name="line.66"></a>
<FONT color="green">067</FONT>       <a name="line.67"></a>
<FONT color="green">068</FONT>       /** */<a name="line.68"></a>
<FONT color="green">069</FONT>       public static final Object processSubstitution(String s, EProperties p, <a name="line.69"></a>
<FONT color="green">070</FONT>                                                      Class returnType) {<a name="line.70"></a>
<FONT color="green">071</FONT>          return processSubstitution(s, p, returnType, 0);<a name="line.71"></a>
<FONT color="green">072</FONT>       }<a name="line.72"></a>
<FONT color="green">073</FONT>       <a name="line.73"></a>
<FONT color="green">074</FONT>       ///////////////////////////////////////////////////////////////////////<a name="line.74"></a>
<FONT color="green">075</FONT>       /////////////////////////  PRIVATE METHODS  ///////////////////////////<a name="line.75"></a>
<FONT color="green">076</FONT>       ///////////////////////////////////////////////////////////////////////<a name="line.76"></a>
<FONT color="green">077</FONT>       <a name="line.77"></a>
<FONT color="green">078</FONT>       <a name="line.78"></a>
<FONT color="green">079</FONT>       /** */<a name="line.79"></a>
<FONT color="green">080</FONT>       private static final boolean isCompleteToken(String s) {<a name="line.80"></a>
<FONT color="green">081</FONT>          Matcher matcher=COMPLETE_PATTERN.matcher(s);<a name="line.81"></a>
<FONT color="green">082</FONT>          return matcher.matches();<a name="line.82"></a>
<FONT color="green">083</FONT>       }<a name="line.83"></a>
<FONT color="green">084</FONT>       <a name="line.84"></a>
<FONT color="green">085</FONT>       /** */<a name="line.85"></a>
<FONT color="green">086</FONT>       private static final Object processSubstitution(String s, EProperties p, <a name="line.86"></a>
<FONT color="green">087</FONT>                                                       Class returnType, int iter) {<a name="line.87"></a>
<FONT color="green">088</FONT>          if (returnType == null)<a name="line.88"></a>
<FONT color="green">089</FONT>             returnType=Object.class;<a name="line.89"></a>
<FONT color="green">090</FONT>          <a name="line.90"></a>
<FONT color="green">091</FONT>          if (returnType.equals(String.class)) {<a name="line.91"></a>
<FONT color="green">092</FONT>             Object rval= recursiveReplace(s, p, iter);<a name="line.92"></a>
<FONT color="green">093</FONT>             if (rval == null)<a name="line.93"></a>
<FONT color="green">094</FONT>                return rval;<a name="line.94"></a>
<FONT color="green">095</FONT>             <a name="line.95"></a>
<FONT color="green">096</FONT>             if (rval instanceof String) <a name="line.96"></a>
<FONT color="green">097</FONT>                return rval;<a name="line.97"></a>
<FONT color="green">098</FONT>             else {<a name="line.98"></a>
<FONT color="green">099</FONT>                log.warn("processSubstitution called with String.class, "+<a name="line.99"></a>
<FONT color="green">100</FONT>                      "but result is "+rval.getClass().getName());<a name="line.100"></a>
<FONT color="green">101</FONT>                return s;<a name="line.101"></a>
<FONT color="green">102</FONT>             }<a name="line.102"></a>
<FONT color="green">103</FONT>          } else {<a name="line.103"></a>
<FONT color="green">104</FONT>             if (isCompleteToken(s)) {<a name="line.104"></a>
<FONT color="green">105</FONT>                return completeReplace(s, p, iter);<a name="line.105"></a>
<FONT color="green">106</FONT>             } else {<a name="line.106"></a>
<FONT color="green">107</FONT>                return recursiveReplace(s, p, iter);<a name="line.107"></a>
<FONT color="green">108</FONT>             }<a name="line.108"></a>
<FONT color="green">109</FONT>          }<a name="line.109"></a>
<FONT color="green">110</FONT>       }<a name="line.110"></a>
<FONT color="green">111</FONT>       <a name="line.111"></a>
<FONT color="green">112</FONT>       /**<a name="line.112"></a>
<FONT color="green">113</FONT>        * This is replacing a complete key - but should work the same as<a name="line.113"></a>
<FONT color="green">114</FONT>        * the partial replace if the value returned by the token lookup is a<a name="line.114"></a>
<FONT color="green">115</FONT>        * String.  */<a name="line.115"></a>
<FONT color="green">116</FONT>       private static final Object completeReplace(String s, EProperties p, <a name="line.116"></a>
<FONT color="green">117</FONT>                                                   int iter) {<a name="line.117"></a>
<FONT color="green">118</FONT>          log.debug("Complete replace of token '"+s+"'");<a name="line.118"></a>
<FONT color="green">119</FONT>          <a name="line.119"></a>
<FONT color="green">120</FONT>          SubstitutionToken subToken=new SubstitutionToken(s);<a name="line.120"></a>
<FONT color="green">121</FONT>          String key=subToken.getKey();<a name="line.121"></a>
<FONT color="green">122</FONT>          String def=subToken.getDefault();<a name="line.122"></a>
<FONT color="green">123</FONT>          <a name="line.123"></a>
<FONT color="green">124</FONT>          Object val=p.findValue(key);<a name="line.124"></a>
<FONT color="green">125</FONT>          <a name="line.125"></a>
<FONT color="green">126</FONT>          if (val == null) {<a name="line.126"></a>
<FONT color="green">127</FONT>             return def;<a name="line.127"></a>
<FONT color="green">128</FONT>          } else {<a name="line.128"></a>
<FONT color="green">129</FONT>             if (val instanceof String) {<a name="line.129"></a>
<FONT color="green">130</FONT>                String sval=(String)val;<a name="line.130"></a>
<FONT color="green">131</FONT>                log.debug("Complete replace, result is string '"+sval+"'");<a name="line.131"></a>
<FONT color="green">132</FONT>                if (containsTokens(sval)) {<a name="line.132"></a>
<FONT color="green">133</FONT>                   return processSubstitution(sval, p, Object.class, iter);<a name="line.133"></a>
<FONT color="green">134</FONT>                }<a name="line.134"></a>
<FONT color="green">135</FONT>             }<a name="line.135"></a>
<FONT color="green">136</FONT>             return val;<a name="line.136"></a>
<FONT color="green">137</FONT>          }<a name="line.137"></a>
<FONT color="green">138</FONT>       }<a name="line.138"></a>
<FONT color="green">139</FONT>       <a name="line.139"></a>
<FONT color="green">140</FONT>       /**<a name="line.140"></a>
<FONT color="green">141</FONT>        * This is replacing a partial key.<a name="line.141"></a>
<FONT color="green">142</FONT>        */<a name="line.142"></a>
<FONT color="green">143</FONT>       private static final Object recursiveReplace(String s, EProperties p, int iter) {<a name="line.143"></a>
<FONT color="green">144</FONT>          // the word 'recursive' in this sense is really a recursion to support<a name="line.144"></a>
<FONT color="green">145</FONT>          // nested tokens.  Which is why it cannot fix the other, different<a name="line.145"></a>
<FONT color="green">146</FONT>          // recursion problem noted below.<a name="line.146"></a>
<FONT color="green">147</FONT>          // The recursion here is to support nested keys, like this:<a name="line.147"></a>
<FONT color="green">148</FONT>          // env=test<a name="line.148"></a>
<FONT color="green">149</FONT>          // foo=${env-&gt;${env}}<a name="line.149"></a>
<FONT color="green">150</FONT>          // Above, 'foo' has a value that is nested.  the 'recursion' of this <a name="line.150"></a>
<FONT color="green">151</FONT>          // method is to support such nesting.  In the above case, we would<a name="line.151"></a>
<FONT color="green">152</FONT>          // go thru iter: 0, 1, 2 (where 2 doesn't really do anything).<a name="line.152"></a>
<FONT color="green">153</FONT>          <a name="line.153"></a>
<FONT color="green">154</FONT>          <a name="line.154"></a>
<FONT color="green">155</FONT>          // FIXME: This class allows recursive replace - which should not<a name="line.155"></a>
<FONT color="green">156</FONT>          // be allowed!!  <a name="line.156"></a>
<FONT color="green">157</FONT>          // Here, recursive replace is defined as the following:<a name="line.157"></a>
<FONT color="green">158</FONT>          //   key.a=${key.b}<a name="line.158"></a>
<FONT color="green">159</FONT>          //   key.b=${key.a}<a name="line.159"></a>
<FONT color="green">160</FONT>          // Which is valid syntax.  (and more common when we consider included<a name="line.160"></a>
<FONT color="green">161</FONT>          // properties files).<a name="line.161"></a>
<FONT color="green">162</FONT>          // <a name="line.162"></a>
<FONT color="green">163</FONT>          // The real solution is not the iter parameter, but a<a name="line.163"></a>
<FONT color="green">164</FONT>          // ThreadLocal variable that counts the recursion.<a name="line.164"></a>
<FONT color="green">165</FONT>          //<a name="line.165"></a>
<FONT color="green">166</FONT>          // The key point here though is that we'd have a better error message<a name="line.166"></a>
<FONT color="green">167</FONT>          // but it would still be an error.  It will error either way.  If<a name="line.167"></a>
<FONT color="green">168</FONT>          // we don't put in the thread local counter, it will result in a <a name="line.168"></a>
<FONT color="green">169</FONT>          // stack overflow.<a name="line.169"></a>
<FONT color="green">170</FONT>          <a name="line.170"></a>
<FONT color="green">171</FONT>          if (iter &gt; MAX_RECURSIVE_SUBSTITUTIONS)<a name="line.171"></a>
<FONT color="green">172</FONT>             throw new RuntimeException("Error: recursive replacement limit on '"+<a name="line.172"></a>
<FONT color="green">173</FONT>                   s+"' "+iter+" exceeds max "+MAX_RECURSIVE_SUBSTITUTIONS);<a name="line.173"></a>
<FONT color="green">174</FONT>          <a name="line.174"></a>
<FONT color="green">175</FONT>          // Note: Pattern instance is immutable and thread safe.<a name="line.175"></a>
<FONT color="green">176</FONT>          Matcher matcher = PARTIAL_PATTERN.matcher(s);<a name="line.176"></a>
<FONT color="green">177</FONT>          <a name="line.177"></a>
<FONT color="green">178</FONT>          String newVal = s;<a name="line.178"></a>
<FONT color="green">179</FONT>          while (matcher.find()) {<a name="line.179"></a>
<FONT color="green">180</FONT>             log.debug("replace: found tokens in '"+s+"'");<a name="line.180"></a>
<FONT color="green">181</FONT>             <a name="line.181"></a>
<FONT color="green">182</FONT>             // value=something ${key|default} something else<a name="line.182"></a>
<FONT color="green">183</FONT>             // token will be '${key|default}<a name="line.183"></a>
<FONT color="green">184</FONT>             String token = s.substring(matcher.start(), matcher.end());<a name="line.184"></a>
<FONT color="green">185</FONT>             log.debug("   Token: '"+token+"'");<a name="line.185"></a>
<FONT color="green">186</FONT>             <a name="line.186"></a>
<FONT color="green">187</FONT>             SubstitutionToken subToken=new SubstitutionToken(token);<a name="line.187"></a>
<FONT color="green">188</FONT>             String key=subToken.getKey();<a name="line.188"></a>
<FONT color="green">189</FONT>             String def=subToken.getDefault();<a name="line.189"></a>
<FONT color="green">190</FONT>             <a name="line.190"></a>
<FONT color="green">191</FONT>             <a name="line.191"></a>
<FONT color="green">192</FONT>             String replaceVal = p.findProperty(key);<a name="line.192"></a>
<FONT color="green">193</FONT>    <a name="line.193"></a>
<FONT color="green">194</FONT>             if (replaceVal != null) {<a name="line.194"></a>
<FONT color="green">195</FONT>                log.debug("   Found value for token "+token+": "+replaceVal);<a name="line.195"></a>
<FONT color="green">196</FONT>                newVal = newVal.replace(token, replaceVal);<a name="line.196"></a>
<FONT color="green">197</FONT>             } else {<a name="line.197"></a>
<FONT color="green">198</FONT>                if (def != null) {<a name="line.198"></a>
<FONT color="green">199</FONT>                   log.debug("   No value for token "+token+", using default: "+def);<a name="line.199"></a>
<FONT color="green">200</FONT>                   newVal=newVal.replace(token, def);<a name="line.200"></a>
<FONT color="green">201</FONT>                }<a name="line.201"></a>
<FONT color="green">202</FONT>                else {<a name="line.202"></a>
<FONT color="green">203</FONT>                   // nothing - this will fail by design.<a name="line.203"></a>
<FONT color="green">204</FONT>                }<a name="line.204"></a>
<FONT color="green">205</FONT>             }<a name="line.205"></a>
<FONT color="green">206</FONT>          }<a name="line.206"></a>
<FONT color="green">207</FONT>    <a name="line.207"></a>
<FONT color="green">208</FONT>          if (newVal.equals(s))<a name="line.208"></a>
<FONT color="green">209</FONT>             return newVal; // no change<a name="line.209"></a>
<FONT color="green">210</FONT>          else<a name="line.210"></a>
<FONT color="green">211</FONT>             return processSubstitution(newVal, p, null, iter+1);<a name="line.211"></a>
<FONT color="green">212</FONT>       }<a name="line.212"></a>
<FONT color="green">213</FONT>       <a name="line.213"></a>
<FONT color="green">214</FONT>       /** */<a name="line.214"></a>
<FONT color="green">215</FONT>       static class SubstitutionToken {<a name="line.215"></a>
<FONT color="green">216</FONT>          private String key=null;<a name="line.216"></a>
<FONT color="green">217</FONT>          private String def=null;<a name="line.217"></a>
<FONT color="green">218</FONT>          <a name="line.218"></a>
<FONT color="green">219</FONT>          /** <a name="line.219"></a>
<FONT color="green">220</FONT>           * Constructor takes a complete token, in the following form: <a name="line.220"></a>
<FONT color="green">221</FONT>           * ${key} or ${key|def}<a name="line.221"></a>
<FONT color="green">222</FONT>           * ie, the default value is optional.<a name="line.222"></a>
<FONT color="green">223</FONT>           */<a name="line.223"></a>
<FONT color="green">224</FONT>          public SubstitutionToken(String s) {<a name="line.224"></a>
<FONT color="green">225</FONT>             String tokenKey = s.substring(2, s.length() - 1);<a name="line.225"></a>
<FONT color="green">226</FONT>             int pipeindex=tokenKey.indexOf("|");<a name="line.226"></a>
<FONT color="green">227</FONT>             if (pipeindex != -1) {<a name="line.227"></a>
<FONT color="green">228</FONT>                key=tokenKey.substring(0, pipeindex);<a name="line.228"></a>
<FONT color="green">229</FONT>                def=tokenKey.substring(pipeindex+1);<a name="line.229"></a>
<FONT color="green">230</FONT>             } else {<a name="line.230"></a>
<FONT color="green">231</FONT>                key=tokenKey;<a name="line.231"></a>
<FONT color="green">232</FONT>             }<a name="line.232"></a>
<FONT color="green">233</FONT>          }<a name="line.233"></a>
<FONT color="green">234</FONT>          public String getKey() {<a name="line.234"></a>
<FONT color="green">235</FONT>             return key;<a name="line.235"></a>
<FONT color="green">236</FONT>          }<a name="line.236"></a>
<FONT color="green">237</FONT>          public String getDefault() {<a name="line.237"></a>
<FONT color="green">238</FONT>             return def;<a name="line.238"></a>
<FONT color="green">239</FONT>          }<a name="line.239"></a>
<FONT color="green">240</FONT>       }<a name="line.240"></a>
<FONT color="green">241</FONT>    }<a name="line.241"></a>




























































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